C ±ê×¼¿â º¯Êý Ô´´úÂëµÄʵÏÖ ºÍ ·ÖÎö

//¿âº¯ÊýʵÏÖ
char *strcat (char *dst, const char *src)
{
  char *p = dst;
  while (*p)
    p++;
  while ((*p++ = *src++))
    ;
  return dst;
}
char *strncat (char *s1, const char *s2, long unsigned int n)
{
  char *dest = s1;
  char c;
  while (*s1) s1++;
 c = '\0';
  while (n > 0)
 {
      c = *s2++;
  *s1++ = c;
      if (c == '\0')
  return dest;
      n--;
    }
  if (c != '\0')
    *s1 = '\0';
  return dest;
}
 
char * strcpy (char *d, const char *s)//
{
  char *r = d;
  while ((*d++ = *s++));
  return r;
}
char *strncpy (char *s1, const char *s2, long unsigned int n)
{
  char *dest = s1;
  for (; *s2 && n; n--) //n Èç¹û´óÓÚs2µÄ³¤¶È£¬ÔòÉèÖÃ0
    *s1++ = *s2++;
  while (n--)
    *s1++ = 0;
  return dest;
}
void * memcpy (void *dst, const void *src, long unsigned int n)
{
  const char *srcp;
  char *dstp;
  srcp = src;
  dstp = dst;
  while (n-- != 0)
    *dstp++ = *srcp++;
  return dst;
}
void *memmove (void *dst, const void *src, long unsigned int n)
{
  const char *srcp;
  char *dstp;
  srcp = src;
  dstp = dst;
  if (srcp < dstp)
    while (n-- != 0)
      dstp[n] = srcp[n];
  else
    while (n-- != 0)
      *dstp++ = *srcp++;
  return dst;
}
void *memset (void *dst, int c, long unsigned int n)
{
  while (n-- != 0)
    n[(char *) dst] = c; // ¼´ (char*)dst[n] = c;
  return dst;
}
¿âº¯ÊýÁ¦Çó¼ò½à£¬Òò´Ë´æÔÚÒ»¶¨µÄ°²È«µÄÎÊÌ⣬ÕâÊÇÔÚʹÓùý³ÌÖÐÌرð×¢ÒâµÄµØ·½¡£Ò²Òò´ËVC2005²ÅÍƳö_sµÄËùνµÄ°²È«º¯Êý¡£Ò²¾ÍÊǶà¼ÓÁËÅжÏλ¡£